Littoral is:
a leaflike structure located at the end of the abdomen of damselfliesthe lower lip or most posterior whole mouth part of the insect head
the dorsal surface of the first most anterior thoracic segment within the bottom substrate of lakes or streamsthe near-shore zone of ponds and lakes

Lamella is the upper lip or most anterior unpaired mouthpart of the insect head
a leaflike structure located at the end of the abdomen of damselflies

Hilsenhoff, W. L. 1992. Dytiscidae and Noteridae of Wisconsin (Coleoptera). I. Introduction, key to genera of adults, and distribution, habitat, life cycle, and identification of species of Agabetinae, Laccophilinae and Noteridae. Great Lakes Entomologist 25:57-69.

Malcolm, S. E. 1971. The water beetles of Maine: Including the families Gyrinidae, Halplidae, Dytiscidae, Noteridae, and Hydrophilidae. University of Maine, Life Sciences and Agriculture Experiment Station Technical Bulletin 48. 49 pp.

Malcolm, S. E. 1971. The water beetles of Maine: Including the families Gyrinidae, Halplidae, Dytiscidae, Noteridae, and Hydrophilidae. University of Maine, Life Sciences and Agriculture Experiment Station Technical Bulletin 48. 49 pp.

Merritt, R. W. & K. W. Cummins (eds.). 1996. An introduction to the aquatic insects of North America. 3rd ed. Kendall/Hunt Publishing Company, Dubuque, Iowa. 862 pp. [an updated 4th edition goes to the publisher this year]. will permit the identification of all aquatic Diptera to family and most to genus.References to species identification are included in this book:

Useful keys to genus and species that have been published since the 1996 edition of Merritt & Cummins are the following:

Blephariceridae:

Courtney, G. W. 2000. Revision of the net-winged midges of the genus Blepharicera Macquart (Diptera: Blephariceridae) of eastern North America. Memoirs of the Entomological Society of Washington 23:1-99.

Culicidae:

Darsie, R. F. & R. A. Ward. 2004. Identification and geographical distribution of the mosquitoes: of North America, north of Mexico. University Press of Florida, Gainesville, FL. 400 pp.